The present invention relates to scene analysis apparatus and methods and more particularly, to a method and apparatus for analyzing a scene at two different resolutions.
In many areas of particle analysis, such as, blood cell analysis or pap smear analysis, the particles of interest are widely distributed in a field and are surrounded by many particles of no interest at all. For example, white blood cells may be surrounded by hundreds of red blood cells while cancerous or dysplastic cervical cells may be surrounded by tens-to-thousands of normal cervical cells and debris.
It is desirable to analyze only the particles of interest in the scene. This can be done by analyzing all of the objects in order to exclude the unwanted objects. However, this technique is very time-consuming and therefore relatively impractical from a commercial standpoint. Alternately, one can use a single sensor to search for particles of interest at a low resolution and then switch the sensor to a higher resolution for analysis when a particle of interest is found in the sample. However, this method requires mechanical or electrical switching of the analysis resolution with a concomitant limitation of a single mode of operation at any given time.
It is accordingly, a general object of the invention to provide a method and apparatus for scene analysis which overcomes the limitations of the prior art systems.
It is specific object of the invention to provide a method and apparatus for dual resolution analysis of a scene.
In the accomplishment of these objects, two sensors are employed; one covering a large field at a low resolution and the other covering a small field at a higher resolution. The low resolution field of view (large field) is located in a known relationship to the higher resolution field of view (the small field). Given the known relationship of the resolution fields, when an object of interst is detected in the low resolution field, it can be moved into the higher resolution field for further detailed analysis while continuing the analysis of the scene or sample at the low resolution to detect any other objects of interest. Thus a plurality of degrees of resolution analysis can occur substantially simultaneously.